MBTA Transit Police said they received multiple calls about a person being hit by the train around 6:40 p.m.

Emergency crews went to the scene and after a preliminary investigation found an unidentified 42-year-old woman had been killed by a northbound train while trespassing on the tracks.

Two firefighters were injured during the rescue attempt while trying to confirm power was shut off on the tracks.

"It's a machine that they have," Boston Fire Department District Fire Chief Paul Burke said. "They put a clamp on the third rail and a clamp on the regular train rail to see if it's energized just to confirm the power is shut down. So, that's what they did. There was a slight arcing."

The injuries were minor, officials said, and they were able to keep working.